1. Field of the Invention
The present invention relates to a magneto-optical recording apparatus enabling so-called one beam direct verification, in which erasing, recording, and verifying of information may be conducted with a single light beam in a single process.
2. Related Background Art
Recently, one beam direct verification has been studied to simultaneously check whether information is correctly recorded in recording of information with a single light beam, in order to increase a recording speed and to simplify a construction of the apparatus. For example, such verification is described in Japanese Patent Application No. 3-175159, and proposed is a magneto-optical recording method in which a magneto-optical recording medium is of a double layer structure, information is recorded by a magnetic field modulation method, and a reflection light (or Kerr rotation angle) of a light beam for recording is identified while recording the information to conduct the verification of the recording information. The magneto-optical recording method may enjoy such advantages as an increase in recording speed and simplification of construction of the apparatus without necessity of complex position adjustment of the light beam.
In the above-described conventional example, there is, however, a deviation caused between a region to which a recording laser beam is radiated (as will be referred to as a light spot) and a region in which a coercive force of a recording medium is lessened, so that there may exist in the light spot area a region where the coercive force of the recording medium is lessened (a region which has reached a Curie temperature of the medium) and a region where the coercive force of the recording medium is sufficiently high (a region which has not yet reached the Curie temperature). Thus, old information as recorded before exists in the region which has not reached the Curie temperature of the recording medium. On the other hand, new information under current recording is provided in the region which has reached the Curie temperature of the recording medium. Therefore, there are the old information and the new information mixed in the light spot. Then, when the reproduction is performed by using the reflection light (or Kerr rotation angle) of the recording laser beam, the new information is read out including the old information component. As the old information component increases in the reproduction signal, such a problem becomes outstanding that quality of a signal for verification is degraded due to cross talk of the old information.